For this case, the first thing to do is find the area of the trapezoid.
 We have then:
 [tex]A = (1/2) * (b1 + b2) * (h)
[/tex]
 Where,
 b1: b2: Trapezoid bases
 h: height of the trapezoid
 Substituting values we have:
 [tex]A = (1/2) * (12 + 14) * (15)
A = 195 ft ^ 2[/tex]
 Then, the cost per square foot is given by:
 [tex]C = 5.50A
C = 5.50 * 195
C = 1072.5[/tex]
 Answer:
 The new carpet for the room will cost:
 C = 1072.5 $